Final Report Year
2014
Final Report Abstract
In the frame of the DFG project “Lenga modelling”, the “dynamics of Patagonian Lenga-forests (Nothofagus pumilio) in Chile” were studied at two long-term investigation sites of the cooperation partner at the University of Chile of Santiago. Field data were acquired in two field campaigns and involved structural surveys, increment coring and stem analyses. The aim of the proposed project was to model Lenga forest dynamics with an individual treebased modelling approach. The resulting model was named and can simulate Lenga forest development under natural and managed conditions in six site classes. To avoid the high data requirements for a stable parameterization of individual tree-based models, directly requires stand level growth parameters for model calibration. Model core is the Reineke relation (Reineke 1933) which assumes an allometric (power) function between tree number per ha N_ha and root mean square diameter dq in even-aged stands. Although the Reineke relation operates at stand scale, calibrates tree parameters so that tree growth only depends on the attributes of the individual tree and its neighbourhood. This ensures that the model can be applied also to heterogeneous forest scenarios with local density and age variation.
A novelty and challenge was the inclusion of regeneration and old growth in an individual treebased model. Unlike the main growth phase, the regeneration and old growth module were not validated in the frame of the project. But it could be shown that already simple parameter estimates render plausible scenarios of natural forest (gap) dynamics. The project builds upon and contributes to a long tradition of Chilean-German cooperation in forest science, and investigation in Lenga forest has always been a part of it. Over time, the focus of attention has shifted from intervention in natural forests to the management of the regenerating forest. The individual tree-based model that was developed in this project can be very useful here and hopefully supports the sustainable management of the resource Lenga.
Publications
- (2014). Using Reineke to self-calibrate mortality in individual tree based forest growth modelling. FowiTaTagung, Dresden, 17.-20.09.
Mette T
